Cons

The Alpine PDX-4.150 is a 4/3/2 channel density digital amplifier sporting 150 watts of power for 4 channels. It shares a uniform size with the rest of the series (10-1/8" Width, 7-9/16" Height, 2-7/16" Depth) making it easy to expand the system and stack them to save space. However, the Alpine PDX amplifiers cannot be installed in any manner other than parallel to the floor without voiding the warranty. Some of its features include a 4-Layer glass epoxy PC board, a non-fading pre-amp RCA output, adjustable gain control, a speaker quick connect plug, a subsonic (infrasonic) filter, STAR topology, protection circuits, a power/status LED, a low pass filter, and the same power output for 2Ω or 4Ω loads. The Alpine PDX-4.150, like the others in the series, is CEA-2006 compliant, meaning it passed the new system of testing and measurement for mobile audio amplifiers.